1. Field of the Invention
The present invention relates to a device for guiding material webs in rotary presses, in particular rotary presses used for producing print runs having different print volumes.
2. Background of the Invention
German Patent Application No. 195 39 693 A1 describes a device for pulling off superposed webs in a rotary press. In this related art configuration, a draw-off roller is provided between a print unit and a folding device; the draw-off roller is driven with a circumferential speed and set into a rotation that is adjusted to be higher than that of an impression cylinder. Provision is made for a plurality of pressure rollers, which are able to be forced to engage or disengage with the margins at both ends of a plurality of printed webs, which are laid one over another and around the outer peripheral area of the draw-off roller. The pressure rollers are rotatable and are provided at both ends along the outer peripheral surface of the draw-off roller. A pressing device is also provided for pressing the pressure rollers onto the margins at both ends of the printed webs, which are laid around the outer peripheral area of the draw-off roller. The multiplicity of the printed webs supplied by the print unit are laid one over another and guided around the outer peripheral surface of the draw-off roller, are each pressed at their margins, at both ends, by a plurality of pressing webs, against the outer peripheral surface of the draw-off roller, and pulled off by the driving and rotation of the draw-off roller, to ultimately arrive in the folding device.
German Patent Application No. 41 28 797 A1 refers to a paper web guide assembly in rotary presses. In the case of a paper web guide assembly for rotary presses having six plate-width printing cylinders, the object is to achieve substantial flexibility in the variation of paper web ribbons or segments with little outlay for equipment. Six folder formers are arranged on three planes for the paper web ribbons. This enables greater variability to be achieved in the mixing and uniting of individual ribbons, thereby substantially enhancing production flexibility, for example in a newspaper rotary press.
Japanese Patent Document No. 5-27402-U is directed to a folding device for rotary presses. Folding apparatuses, which are arranged downstream from rotary presses, include a plurality of folding sections. Two inner folding devices are provided, two folder formers being arranged in pairs; two formers are provided on a top plane, two others on a bottom plane; two outer folding units are mounted at both sides of the angle-bar superstructure at the level of the two inner folding units, a small clearance remaining therebetween. Also provided is a pull roller, which cooperates with a slitting knife, which longitudinally slits a material web being fed to the inner folding units. There are two angle-bar decks, so that the web path of one of the two longitudinally slit web halves can be exchanged for the other.
German Patent No. 32 37 504 C2 discusses a paper web for rotary presses. A paper web guiding mechanism is provided in a rotary press having a number of paper web guide rollers between printing units and formers of a folding apparatus. At least two formers are disposed side-by-side on a common horizontal plane, and at least one slitting device is provided for dividing a paper web into a remaining web and one partial web per paper web. Also provided on the same plane directly adjacent to the other folder formers, is an additional folder former that extends beyond the maximum paper web width. The paper web guide rollers upstream from a former infeed roller are designed to be at least one fourth longer than a maximum width of one of the printable paper webs in the printing units. For each paper web, two angle bars are provided, one of which is displaceably mounted transversely to the paper web""s direction of travel.
Newspaper production often requires printing several editions on rotary presses. The editions are prepared in larger or smaller print runs, depending on whether they are intended for larger or smaller distribution regions. For that reason, several different rotary presses are needed to be able to print the editions one after another.
When one single edition is produced on merely one rotary press and, in fact, in successive intervals, this leads to a longer production time for the total edition. Inevitably, the decision to print one edition on two rotary presses is made in view of the large capital investments required for the second printing machine.
On the basis of the related art approaches outlined here, an object of the present invention is to produce print runs of different lengths independently of one another on a double-width rotary press.
The present invention provides a device for guiding material webs (A, B, C, D; E, F, G, H), via an angle-bar deck (2) of a folding section that is subdivided into a plurality of planes (3.1, 3.2, 3.3), from where the material webs (A through D), (E through H) enter folding apparatuses (4), (5). The present invention is characterized in that accommodated on longitudinal folding devices (8), (9) are infeed elements (7), which have guide sections (13), (14), which are able to be operated independently of one another.
There are many diverse advantages associated with the device according to the present invention. Subdividing the rotating guide element into guide sections that can be operated independently of one another allows a rotary press to be continuously operated to produce a large print run; on the other hand, a smaller print run can be produced independently of the large print run. This smaller print run can be guided over one of the independent guide sections, without have any adverse effect on the printing of the large print run. Thus, a double-wide newspaper rotary press makes it possible to independently and simultaneously produce different-volume print runs. Printing of the long print run can continue after the short print run is already finished printing, so that an additional print job can be prepared on the remaining, now available guide section. When working with newspaper and commercial web presses, the editions usually include completely identical sections, and are distinguished from one another only by inserts or local sections. These inserts or local sections can be printed individually in smaller, i.e. short print run, editions, independently of a longer print job, and simultaneously on one and the same rotary press.
In one advantageous refinement of the inventive idea, the guide element is fashioned, for example, as a former infeed roller and arranged above a folder former of one or a plurality of folder formers. A separate drive can be assigned to each of the two guide sections, it being possible for the drives to be driven independently of one another.
The former infeed-roller surfaces forming a traversing, rotating surface are rotatable with respect to one another and can be joined to one another, for example by way of a free-wheeling mechanism which permits both guide roller sections to rotate in common, as well as, in each case, separately with respect to one another. A mounting support for the former infeed roller that takes up as little construction space as possible is achieved by using one of the guide roller sections as a mounting support for the other guide roller section.
For that, a projection of a guide roller sectionxe2x80x94for example, a bearingxe2x80x94can engage with form locking in a recess at the other guide section. Besides a free-wheeling mechanism, a coupling, a neck-recess bearing arrangement, other devices, such as ball bearings, lubricated sleeve bearings, and the like would be quite suited for enabling independent rotation between the guide sections.
The folding sections in the superstructure each contain a plurality of longitudinal folding units. A plurality of longitudinal folding units can be mounted side-by-side in the folding apparatus superstructure. The longitudinal folding units are able to be positioned side-by-side, in pairs, for example, on three planes, thereby facilitating great variability in production when working with newspaper rotary presses.
Rotating web guide rollers in the superstructure, downstream from the dryer, in the cooling roller section, as well as upstream from the printing units in the imprinting unit area, can likewise be equipped quite advantageously with roller sections capable of being operated independently of one another. The web guidance can be so conceived that, during printing, parts of the web traverse all printing units, while other parts are guided, above or below individual print units, by-passing the same. This kind of flexibility is necessary if one is to always effectively utilize newspaper printing presses to capacity, as they represent substantial investments. The device proposed by the present invention further enhances the effective utilization of a printing press to capacity.
The web guide roller, which can be used, for example, as a former infeed roller, can be operated in superstructures both with and without slitting devices, the provision of slitting devices further enhancing the flexibility and versatility of a rotary press. The divided web guide roller is preferably used in newspaper rotary presses, however its application in commercial web presses is conceivable.